It's all in the legs, not the arm. The secret is in the length of your stride. Lincecum's stride is almost twice as long as other pitcher's, one of the main purposes of his funky delivery. Maddux, Clemens had big strides too.
But the one that sticks out in my mind was Seaver's. He used to wear out a hole in the right knee of his pants with every start.
